schaer



C. SCHAER.

APPARATUS FOR DISTILLING TAR.

APPLICATION man MAY 21. 1920.

1,415,057, Patented May 9, 1922.

3 SHEETS-SHEET I- {WWI I I I I' I 1 II|IHIIIIIIIIII lk/i/ C. SCHAER.

APPARATUS FOR msmums TAR.

APPLICATION HLED MAY 27, 1920.

Patented May 9, 1922.

3 SHEETS-SHEET 2.

c. SCHAER- APPARATUS FOR DISTILLING TAR.

APPLICATION FILED MAY 21, I920- 1,415,057. 7 Patented May 9; 1922.

3 SHEETS-SHEET 3.

CHARLES SCHAER, OF LANGENTI-IAL, SWITZERLAND.

APPARATUS FOR DISTILLING TAR.

Specification of Letters Patent.

Patented May 9, 1922.

Application filed May 27, 1920. Serial No. 384,701.

T 0 all whom it may concern:

Be it known that CHARLES Sornxnn, a citizen of the Republic of Switzerland, residing at and whose post-office address is Langenthal, Switzerland, has invented certain new and useful Improvements in Apparatus for Distilling Tar; and he does hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a method of and apparatus for the recovery of the components of coal tar by distillation and condensation, similar to that disclosed in a copending application, Serial No. 163,985, filed April 23, 1917.

When coal tar (specific gravity between 1.1 and 1.2) is gradually heated, its components are successively released. At a temperature of 340 F. water contained in the tar, to the extent of 4%, is released, considerable ammonia being dissolved in this released water. At the same temperature a series of oils evaporate. These are the light oils having a specific gravity below .95, and to this group belongs benzol, toluol, xylol, etc. When the temperature rises above 340 F., but below 450 F., the medium oils (specific gravity between .95 and 1.02) are distilled off. These oils contain carbolic acid and its homologues. Increasing the temperature above 450 F. causes the dis tillation of the heavy oils which have a specific gravity above 1.02 and. contain creosote, etc. Above 650 F. the heavy oil, which is mainly anthracene with a specific gravity of 1.06 to 1.11, is distilled off. The residue of pitch, which is solid at ordinary temperatures, contains a series of liquid derivatives of still higher specific gravity, which, however, are difficult to abstract because pitch is subject to decomposition if-subjected to heat over a certain temperature, whereupon it forms a solid mass preventing the escape of the vapors. lVhile the above described dis tillation might appear simple theoretically, violent states of ebullition, high temperatures and chemical reactions make the actual distillation a difficult matter.

One object of the present invention is the distillation and condensation of the components of the coal tar in a minimum number of operations, in a continuous operation portion of the plant;

Fig. 2 is a sectional view taken longitudinally through one of the stills on line 22 of 4;

Fig. 3 is a similar view through the other Fig. 4c is a transverse section through both stills;

Fig. 5 is a detail section disclosing the means for spreading the tar on the interior surface of the still in a thin layer;

Fig. 6 is a vertical longitudinal sectional view of the plant;

Fig. 7 is a horizontal section therethrough; anc

Fig. tion.

In F igs'. 1 to 5, inclusive, the distillation portion of the plant is illustrated, and this includes a furnace or kiln 1 which is divided into two compartments 1 and. 1. In these compartments horizontal, cylindrical stills 2 and 3 are located, the level of the still 2 being above that of the still 3, in or der that the tar may flow from still 2 to still 3 by gravity through pipe 35. A fire box 19 is located within the compartment 1", which box includes a grate 20, a coaling door 26, an ash pit 26 and an ash door 27. Extending from the immediate rear of the grate 20 are lines 25 which open into a chan- 1101 21, thus establishing communication di rectly between the grate and the channel. The openings 22 also establish communication between the channel 21 and the grate, but only after the gases pass around the still 8. A flap valve 24 having an operating handie 23 serves to close or partly close the fines 25 and openings 22, and consequently controls the flow of the gases from the grate.

8 is a sectional view of a modifica- All of the gases may be caused to pass through the fines 25 by opening the valve 24: completely, or part may be caused to follow this path and part flow around the still 3. On the other hand, it the valve 2 1 is closed completely all of the gases will pass around the still 3 before reaching the channel 21. This channel 21 communicates with the chamber 1, as shown in Fig. 3, so that the products of combustion, after having had some of the heat absorbed by the material in the still. 3, will pass around the upper still 2 and lose more of their heat. These gases pass from the chamber 1 to the stack 7 and escape. The path of the gases is indicated by the arrows on the drawing.

A tar inlet pipe 38 leading trom a supply tank 38 connected to one endoit the upper still 2 and is provided with a preheater tor the incoming tar, which preheater may be of: any suitable form such, for instance, as coils of pipe 1O, located within the chamber 1. A discharge pipe 35 leading to still 3 extends from the still 2 at the opposite end from that of the supply pipe 38.

The still 2 is provided with an axial shaft 30 mounted in bearings 31 and 32 and having stufling boxes 33, to which shaft rotary motion is imparted by any suitable means such as a belt tiwvhich passes around the pulley 44; on the extended end 30 of the shaft-30 and around a driving pulley 45, which is mounted on a shaft 45, the latter being driven by a belt or other suitable connection with the motor 46. (See Fig. 7). At each end of the shattBO and between the ends thereof, plates '34 are secured and rods 35 extend between these plates. Ladies 35" are pivotally mounted on the rods 35 and are held inposition with their discharge ends adjacent to the interior face of the still by the springs 30, the latter being secured to the shaft 80. These ladles act to distribute the tar over the lace of the still in a thin layer which layer is then scraped oil by the advancing edge of the succeeding ladle, so that by the rotation of the ladles fresh tar is constantfy and repeatedly applied to the heated walls of the still and constantly and repeatedly scraped off without being allowed to carbonize or cake thereon At the same time the tar in the still. is con stantly agitated or stirred by the motion of the ladles the'rethrough, thus preventing ebullition or frothing from accumulation of steam or vapors in the tar. The other still 3 is provided with a tar distributing and stirring mechanism-similar *to that just described and, therei ore,a detailed description. otthlis mechanism is not necessary. How ev'er,it may be stated that the shaft is provided with a pulley is which is actuated by the belt 46 or other suitable means and,therefore, derives its motion from the motor 46.

A vapor outlet pipe-36 extends from the upper still '2 to-carry away the'vapors which are generated in this still and a smaller pipe 37 extends from-the p ipe 35 tOithe pipe dfi "to so that the pitch will pass therethrough at a carry away the vapors generated in the pipe 35 during the passage of the tar from the still 2 to the still 3. A pipe 29 extends from the still 3 to carry off the vapors from this still and a smaller pipe 8 discharges the residue of pitch into a receiver on the end of a relatively long pipe 10 which leads to a pit 11. The pipe 10 is made of considerable length and the end submerged into the pitch comparatively low velocity and will gradually cool without coming in "contact with the air, thereby reducing the chances of spontaneous combustion to the minimum. However, the pitch may be discharged into a covered pitch cooling weir which consists of a compartment C from which the air is excluded, and an overflow compartment C, the pipe 10 extending into the compartment C. A seal pot S is interpolated in the pipe During the passage of the pitch through the pipe 10 "some vapors are released, which vapors are for the most part anthracene, and these vapors are drawn off through the pipe 12 by the suction of a tan let which discharges through an ejector 13 and a pipe 13. These vapors which are condensed in the pipe 13 and flow into a receiver 15 through the pipe 18, the air from the ejector passing off at 13". establish communication between the fan 14 and the stack 7 to create a draft in the latter.

The vapors which pass from the upper or first still through the pipe 36 and from the pipe 37 tothe pipe'36 are of the light oils and-ammonia water. From the pipe 36 these vapors are lead to a condenser 50, whence the condensed liquids flow to a separator tank 51 where the ammonia water settles to the bottom, thusenabling the drawing off of the light oils andammonia water separately and at the same time continuously.

The vapors which escape from the lower or second still. 3 are led through the pipe 29. These vapors are of the medium and heavy oils, and may all be conveyed to condenser 56 and collected in any of the receivers 52, 53 and 5 1. The train-of receivers are put in communication with-each other by means of the valved pipe 55. Means are provided, however, for separating the medium from the heavy oils and collecting them separately. The heavy oils will con dense first, and by having said pipe of suitable length the heavier OllS will condense in said pipe and the condensate is tapped' off at a suitable point by pipe 29 and led therethrough to receiver 'The vapors of the medium oils will, however, pass to the condenser56 through a conduit 57 a2nd thecondensed liquids will pass through aconduit 58 to receiver 54. Itwill be realized, however, that the heaviest oil "will be condensed first in' the pipe 29 and, therefore, I have provided a pipers" whichextends ironTthe *1 a 0 A by-pass 16-17 may 95 i pipe 29 to the receiver 59, the pipe 58 being connected to the pipe 29 adjacent to the still 2. However, the specific gravity of the oil drawn off from the pipe 29 will be determined by the point at which it is taken. Therefore, I contemplate the drawing off of the condensed heavy oil from the pipe 29 at various points in the pipe 29 and thus I may obtain oil of any desired specific gravity.

The pitch flows from the still 3 through the pipe 8 as aforesaid and the vapors are led off through the pipe 13. These vapors, which are mainly of anthracene, are led to and condensed within the condenser 60, which is supplied with water through a pipe 60, whence they flow to the receiver 52.

t will be seen that the tar is completely distilled in two stills during which distillation the light oils and ammonia water are released in the first still and the medium oils and heavy oils are released in the second still. The light oils and ammonia water are condensed in the same condenser 56. Due, however, to the difference in the specific gravity, the light oils may be drawn off con tinuously from the top of the ammonia water. The vapors of the medium oils and heavy oils may pass from the second still to a common condenser. In the passage through pipe 29, however, the oils of the highest specific gravity condense and are thus separated from the remaining heavy oils and medium oils. If the condensed heavy oils are drawn off adjacent to the still the specific gravity will, of course, be higher than if they are drawn off at other points along the conduit from the still to the condenser. Thus oils of various specific gravities may be obtained before the oil vapors reach the condenser. The vapors which pass to the condenser 56 are of the medium oils. These medium oils are here condensed and flow to the storage tank 54. As the pitch flows from the still 3, the vapors are drawn therefrom and are condensed. This results in the production of anthracene. Thus, with two stills and two condensers, five distillates are obtained.

The commercial value of the method and apparatus lies in the facts that the cost of installation is low and the space required is small; the still may be operated continuously, that is to say, the tar distilled continuously, the distillates are discharged continuously and are condensed continuously and the pitch is discharged continuously without the shutting down or cooling of the apparatus; the operating expense is especially low, as a single operator can take care of a number of stills, due to the few operating parts; the efficiency is very high (in actual operation 61.9% oils were obtained with only 36.22% pitch the cost of repairs is small, due to the simplicity of the plant; the operation is safe, due to the fact that no steam is used and that no vacuum exists in the apparatus; the usual odor is absent, due to sucking off of the vapors from the pitch with the resulting addi tional production of anthracene oil; and a harder and better grade of pitch is obtained.

This application is a continuation in part of my co-pending application Serial No. 163,985, filed April 23, 1917.

Vhat I claim is:

1. Apparatus for the distillation of tar comprising the combination of two stills, a single source of heat for said stills, means for controlling the heat to liberate medium and heavy oils in one of said stills and to liberate the lighter oils and ammonia in the other of said stills, a tar discharge conduit connecting the lighter oil still to the heavier oil still, a pitch discharge conduit from the heavier oil still, a condenser for the lighter oils and ammonia connected to the lighter oil still, a condenser for the medium and heavy oils connected to the heavier oil still, a vapor conduit from the pitch discharge, a condenser connected thereto, and means for continuously delivering tar to and through the system.

2. Apparatus for the distillation of tar comprising in combination a furnace having two compartments, a still in each of said compartments, heating flues leading the heating gases to and around each of said stills, means to control the flow of said gases to said stills whereby medium and heavy oils are liberated in one of said stills and ammonia and lighter oils are liberated in the other of said stills, a tar discharge conduit connecting the last mentioned still to the former, a pitch discharge conduit leading from the heavier oil still, means in said stills for stirring the tar therein, a vapor conduit and a condenser connected to the lighter oil still and the discharge conduit therefrom, a vapor conduit and a condenser connected to the heavier oil still, a vapor conduit and condenser connected to the pitch discharge, and means for continuously delivering tar to and through the system.

3. Apparatus for the continuous distillation of tar comprising in combination a furnace having two compartments and a single source of heat, a still in each of said compartments, heating flues leading the heating gases to and around each of said stills, means to control the flow of said gases to said stills whereby medium and heavy oils are liberated in one of said stills and ammonia and lighter oils are liberated in the other of said stills, a preheater in the furnace compartment containing the last mentioned still, a pitch discharge conduit from the heavier oil still, a source of constant tar supply, said preheater, stills and pitch discharge arranged at different levels whereb the tar flows by gravity to and throughthe preheater, lighter oil still and heavier oil still tothe pitch dischargezin succession, and means for separately condensing and collecting the vapors from each of said stills and the pitch discharge conduit.

4;. Apparatus for the distillation of tar comprising in combination a still for the liberation of the light oils and ammonia, a still for the liberation of the medium and heavy oils, a pitch discharge conduit from. the latter still, means for heating said stills to the appropriate temperature respectively, a conduit for discharging tar from the light oil' still to the heavy oil still, vapor conduits leading from the light oil still and said tar conduit to a common condenser, a vapor conduit leading from the heavy oil still, a branch from said conduit forthe heavy oils condensed therein, a second branch from said conduit for medium oil vapors, a condenser connected to said second branch, a conduit for anthracene vapors leading from the pitch discharge conduit, and means connected to the last conduit for drawing said vapors therethrough to a condenser.

5. Apparatus for the distillation of tar and the recovery therefrom, of ammonia, light oils, medium oils, heavy oils, anthracene and pitch, said apparatus comprising in combination a still for the liberation of ammonial and light oils, a second still for the liberation of medium and heavy oils, a connection for discharging tar from the first to the second still, a vapor conduit from the first still and said tar discharge connec tion to a common condenser for the light oil and ammonia, acond'uit for the medium and heavy oil vapors leading from the second still, a plurality of branches from said conduit at different points therein with respect to the still for leading off the heavy oils of different specific gravities that condense in said conduit, a branch from the end of said conduit for the medium oil vapors, a condenser connected to said branch, a pitch discharge conduit from the second still, a sealed pitch receptacle connected to said conduit, a conduit from said pitch discharge conduit for the anthracene vapors, acondenser to receive said vapors, and means for drawing said vapors throughfsaid conduit to the condenser.

6. Apparatus forthe distillation of tar comprising in combination a still for the liberation of the lighter oils and ammonia, a still for the liberation of the medium and heavier oils, a connection between said stills through which the tar flows from the'first tothe second still, a pitch discharge conduit from the second still, a pipe connected to said pitch conduit for leading vapors therefrom, a suction or exhaust means connected to said pipe, and means for cooling said vapors.

7. Apparatus for the distillation ottar comprising in combination aplurality of stills, means for feeding tar to andthrough said stills in succession, a furnace for heating said stills, a pitch discharge conduit from the last of said stills, a pipe connected to said conduit for leading vapors the-refrom, a blower connected to said pipe forexhausting the vapors therethrou-gh, a pipe leading from the pressure side of said blower to the draftfiue of saidfu-rnace for increasing the draft thereof, and means for cooling the vapors from said vapor pipe.

8. In a tar distillation plant comprising stills for separating light, medium and heavy oils from the tar, means for feeding the tar to said stills in succession, a pitch conduit for discharging pitch from the last of the stills, a blower for exhausting vapors from said conduit, a pipe for receiving said vapors and condensing the-same, and a separator connected to said pipe for separating the condensable from the non-condensable vapors.

In testimony whereof I alfix my signature, in presence of two witnesses.

CHAR-LES SGHAER. Witnesses O. .M. Awmo, J. H. L. LORENTZEN. 

